Cooling System

General Description

Cooling System The engine cooling water is circulated by a thermo-syphon by a water pump and the whole system is pressurised. This both prevents water loss and raises the boiling point. The radiator is cooled by airflow created by forward motion of the vehicle, but whilst the vehicle is stationary this airflow is created by an engine driven fan or an electrically driven fan mounted forward of the engine. 

It must be noted that lack of maintenance in this area can cause overheating and even an expensive seizure of the engine.


This should only be done when the engine is cold. Draining whilst the engine is hot can result in severe damage to the cylinder block and head. 

To drain the system, remove the radiator filler cap and move the heater control to the "Hot"position. Remove the radiator drain plug and the cylinder block drain plug (located on the rear left-hand side of the engine). 

Radiator Drain Tap

Radiator Drain Plug
Remove the radiator drain plug and the cylinder block drain plug (located on the rear left-hand side of the engine).  Cylinder Block Drain Tap


Efficient cooling is maintained by flushing the system once a year before adding anti-freeze. When carrying this out, it is an advantage to remove both top and bottom hoses and back-flush the engine as well as the radiator using a hose pipe. Allowing the anti-freeze solution to remain in the system throughout the summer period affords anti-corrosion protection.The solution, however, should be changed at the beginning of each winter period as the inhibitor becomes exhausted.


Replace both drain plugs and open the heater valve fully. Fill the cooling system with clean (soft) water and run the engine for two to three minutes at around 1500 rpm. Top-up the radiator and replace the filler (pressure) cap.
Radiator Cap

Frost Precautions, Anti-Freeze

The car cannot be completely drained by normal methods. Therefore, frost damage will not be prevented by merely draining the radiator.

Protect the cooling system by using a proprietry anti-freeze having long-life and corrision inhibiting characteristics.

The capacity of the cooling system is 14.25 pints (17 US pints or 8.2 litres).

Protection Afforded by Anti-Freeze

%age Concentration
US Pints
17 oF (-8 oC)
7 oF (-14 oC)
-3 oF (-19 oC)
-20 oF (-29 oC)

Note:- Before putting anti-freeze into an engine, all hoses should be checked for possible cracks and all water hose clips should be checked for tightness. Beware that many cheap hose clips (particularly Ford ones) will cut into the hose and be a source of leaks. Use stainless steel (Marine quality) "Jubilee" clips if possible. If the engine has not previously contained anti-freeze (i.e. a rebuilt engine) or the cylinder head has been removed for maintenance, it is advisable to check the cylinder head bolts for tightness using a torque wrench. This is necessary due to the tendency of anti-freeze to "seek out" leaks and an internal leak via a faulty head gasket could cause great damage within the engine.

Do not overfill the radiator as overflowing of water could reduce the specific gravity of the anti-freeze solution in the cooling system. It must also be noted that if the system requires topiing up, it should be done with the correct anti-freeze solution to prevent dilution and therefore its effectiveness.